Coating composition comprising a vinyl acetate unsaturated carboxylic acid copolymer and an organic base dissolved in an organic solvent and article therewith



United States Patent CGATING CGMPUSITION COMPRISKNG A. VINYL ACETATE UNSATURATED JARBOXYLIC ACID COPOLYMER AND AN .ORGANEC BAdE DES- SQLVED IN AN ORGANIC SOLVENT 'AND ARTICLE THEREWITH Joseph R. Ehrlich, 17 93 Riverside Drive, New Yorlr, N.Y. No Drawing. Filed Apr. 13, 1959, Ser. No. 803,793

23 Claims. (Cl. Zeb -29.6)

My invention relates to new and improved polymeric coating lacquers or coating compositions, new and unproved polymeric coating layers, and a new and improved method of making said compositions and layers.

There are certain well-known grades of copolymers of vinyl-acetate with certain unsaturated acids or anhydride s, containing four carbon atoms, such as maleic, furnenc and crotonic or isocrotonic. These grades of said copolymers react with aqueous alkalies, ammonia and amines to form water-soluble salts.

If the ratio of said unsaturated acids or anhydrides in the copolymer is kept low, say from 0.5% to 5.0% the properties and characteristics of said copolymers are much like those of vinyl acetate homopolymers. Their appearance, solubility in organic solvents, softening or melting points, excellent adhesion to all kind of surfaces, filmforming properties, .insolubility in water, etc. are quite similar to those of polyvinyl acetates. Except that they can form Water soluble salts, as before mentioned, a property which the polyvinyl acetates do not possess.

If the aqueous alkaline material which is being reacted with said copolymers is volatile, such as ammonia or a low boiling amine, such as methylor ethylamine or morpholine, such salts of the copolymers decompose again, when exposed for some time to air or when heated, and revert to the water-insoluble resin. Thus, by dissolving the resin e.g. in an ammonium hydroxide solution, it is possible to prepare an aqueous solution e.g. of the ammonium salt of said copolymer which can be used for casting a film on a surface. After a sufficient long drying time or, in a much shorter time, when heated,

the ammonium salt decomposes into volatile ammoniaand the original copolymer resin, which is water insoluble. Such resin films adhere strongly to surfaces of glass, metal, etc. and cannot be removed with water. They can be removed with solvents or aqueous alkalies. Aqueous solutions of the salts of said co-polymers which are formed with non-volatile alkaline materials, such as sodium hydroxide can also be used to cast a film on a surface, however, such films, after drying, are completely Watersoluble.

Resins of this class can be dissolved in various volatile anhydrous amines, and the solvent can be evaporated to deposit the original resin in the original form, showing that many amines do not react with these resins, in the absence of water. These anhydrous amine solvents include morpholine, pyridine, and mono-iso-propylamine. Hence I believe that the salt formation takes place only in the presence of water.

I use resins of this class which do not hydrolyze in water. This stability to hydrolyzation in water is an important feature. I use resins of this class which can react with an alkaline material in the presence of Water, to provide a water-soluble salt.

In the preferred embodiment of my invention, I dissolve a suitable starting or reactant resin of this class in an organic solvent, which is substantially "neutral and which may be polar or non-polar. This solvent may be anhydrous or substantially anhydrous, preferably with not more than 5 percent of water by weight or volume. These organic solvents are exemplified by many alcohols, such as methanol, ethanol; by many esters as ethyl acetate, butyl acetate; by many ketonm, such as acetone, methyl ethyl ketone; by many hydrocarbons, such as toluene, benzene; and by many chlorinated solvents, such as methylene chloride, per chlor-ethylene.

I also dissolve in said preferably anhydrous solvent at small quantity of an organic nitrogen base, which is substantially non-volatile at 20 C.-30 C. at ordinary atmospheric pressure of 760 millimeters of mercury. The quantity of said organic nitrogen base would be insuflicient to form a water soluble salt with the co-polymer, would it have been reacted with the copolymer in the form of an aqueous solution at room temperature and 760 mm. mercury pressure and in the absence of a solvent.

When the solvent is evaporated, as at 20 C.-30 C., and under said normal pressure, the solutes form a coating film on a base object, which may be made of metal, glass, plastic, and which may have a smooth surface.

This residual dry film (i.e. the film provided by the lacquer upon evaporation of the sol-vent) is inert to water vapor under ordinary atmospheric humidity.

However, if this residual film is wetted with water, I can easily and very quickly strip the film in shriveled form from the base object by mild rubbing or wiping or pulling. The film does not dissolve in water.

If the solution contained a sufiicient amount of the dissolved organic nitrogen base to react sufiiciently with the acidic resin, the wetting with water would form a .salt or salt-like compound in the film, which would be watersoluble.

If the solution contains insufiicient dissolved organic nitrogen base to react completely with the acidic resin, the resulting film, after wetting with water is quickly and easily strippable by mechanical action.

The residual film is insoluble in water, at least to any practical extent.

The final dry film is hydrophilic or waterseusitive in each case, without being necessarily watersoluble.

The coating composition or lacquer may be free from coloring materials, or it may include pigments, and it may also include a \dye or dyes which are soluble in the solventvehicle of the coating lacquer and in the material of the residual coating film. The residual film of the new polymeric film or coating may be lightpermeable or opaque. The coating composition may also include a light-filtering agent which is soluble in said solvent. 'Ihis light-filtering agent becomes part of the residual coating film. I can thus form a residual film of the new polymeric material which is transparent and susbtantially colorless; or which is transparent and has any desired color; or which blocks any selected range of visible or invisible light, such as ultra-violet light in any selected range thereof; or any monochromatic visible light; or which is opaque. The coating lacquer may be supplemented with wetting agents. If the coating composition has a pigment or pigments, saidcomposition may be supplemented with dispersing agents. I can alsoadd dichroic staining materials such as eg iodine and obtain an oriented film by stretching as will be outlined later on in the specification.

As one important feature of my invention, I can prodduce a highly adherent, residual thermoplastic surface film upon a smooth and impervious surface of many materials, such as glass, metal, stone and plastics. This thermoplastic film is inert to water under ordinary conditions, in the absence of mechanical stripping action, such as rubbing, wiping and pulling. The film may be wettable by water. It is sufiicient if the film is hydrophilic, namely, sensitive to water. The coating lacquer may contain a dissolved water-proofing agent, such as a silicone oil. In such case, if water is applied to the dry residual film, the water forms drops on said film, instead of forming a continuous film of water, as in other cases. Still, such a film can be removed after short contact with water, and mechanical stripping action. Such a film can also be removed in one piece, with slight shriveling, by flowing water upon it, without dissolving the film. Such lacquer, made with the use of a waterproofing agent, and the resultant film, are within the scope of this invention. Said resultant film, like the other films, is soluble in an aqueous solution of sodium hydroxide or other alkali, if the aqueous solution is of sufficient concentration. If the coated body is kept in a humid atmosphere, which results in condensing a thin surface film or drops of water on the exposed surface of the coating film, said coating film remains adherent and stable in all respects, in the absence of rubbing or wiping or pulling or flowing water upon it.

The exposed surface of the coating film may even be wetted with a thin film of water at 20 C.30 C., or by condensing steam thereon from boiling water which is at 100 C. In such case, the coating film remains adherent and stable in all respects, and the applied water can be evaporated by air-drying, without weakening the adherence or changing any property of the original coating film, in the absence of rubbing or wiping or pulling.

However, if the exposed surface of the coating film is wetted with water, and the wetted coating film is then rubbed, wiped or pulled, the coating 'film loses its adherence to the applied smooth and impervious surface of the base body so that the coating film can be easily stripped from the base body of glass, metal, stone, plastic. In such case, if not stretched, the coating film may shrivel into a string-like shape. This easy stripping of the coat.- ing film from a smooth and impervious surface is an important advantage.

It is thus possible, as one use, to coat the glass lenses of eyeglasses or glass photographic lenses with a thin transparent film of any selected color, said film being formulated to block any selected portion of the visible light spectrum or any portion of the ultra-violet light spectrum. Prescription eye-glasses can be thus easily converted into sun-glasses of any selected color and lightblocking effect. The coating is stable and adherent under ordinary conditions, but it can be easily removed or replaced by wetting and mechanical action or by alkaline aqueous solution, or by flowing water upon it in a stream. Under ordinary atmospheric conditions, the film remains dry and adherent and stable, so that the unwetted film can be wiped to remove dust without stripping said film. The coating film may be formed on glass windows,

Idriving to .diminish the glare of the headlights of onform layers which are comparatively thick.

coming cars. For such applications organic nitrogen bases can also be used which have a very slow evaporation rate at room temperature of 20 C.30 C. and ordinary atmospheric pressure, instead of being completely non-volatile. In such cases a slightly larger amount of nitrogen base might be added to the coplymer than needed to make the residual film strippable after contact with water, in order to allow for slight evaporation losses of the dry film.

If to such a lacquer type solution iodine is added, which completely dissolves in the solvent or solvents, a film layer can be cast from such a lacquer on a smooth surface, such as glass, cellophane etc. after the solvents have completely evaporated, is moistened with water, it becomes detachable from its base.

' By stripping said film from its base and simultaneously keeping it under tension can be transferred to another,

transparent base where it is allowed to dry while kept in a stretched position. After the stretched film has dried and all water has evaporated the film adheres firmly to the new base. If the new base is a thin transparent plate or sheet the resulting lamination product polarizes light. The original copolymer Without the small quantity of alkaline organic material does neither exhibit such stretchability nor such detachability from a base on which it was cast. a

It is of course well-known to provide removable coatings of water-soluble polyvinyl alcohol and other materials which are applied by means of aqueous coating compositions or to use so-called strip coatings which are 1y whereas the improved coating compositions of this invention are of the quick-drying lacquer type and optionally and preferably of low viscosity, so that the improved liquid coating composition dries to provide the improved residual coating film as quickly as the usual nitro-cellulose lacquer, and deposits a very thin film which is not water soluble, and which can be made transparent and completely non distorting for use on optical lenses. When a film of ordinary water-soluble material such as polyvinyl alcohol, gelatin or water-soluble cellulose ethers is formed they change their properties with the change of atmospheric conditions. They become sticky and/or soft under high humidity and brittle when dry. What is worse, they blister and even lose their adherence when dry. To remove them, when not brittle they have to be washed off with water, and when a water soluble dyestuif was dissolved in such film, undesired staining and bleeding of the dye is unavoidable when such film is removed by washing and dissolving.

The so-called strip coatings are based on the fact that film-forming compositions are being used which have very little or no adherence at all to their base, so that they can be pulled og easily. There are certain hot-melt compositions, containing certain types of cellulose acetate butyrate or cellulose acetate which are quite viscous and If such a hot-melt gets in contact with a cold surface, as by dipping or spraying, the chilling effect causes a spontaneous V shrinking effect on the contact face of the coating which prevents adhesion. Strip coatings from solvent solutions can only be made with film-forming materials of poor adhesion, such as certain unplasticized types of cellulose acetate; such coatings are necessarily very brittle and have a tendency to flake off. I

The improved films of this invention, compared with the before mentioned removable films known to the present art, are inert to changes in the humidity of the atmos When said film,

phere; they can be produced in very thin layers, e.g. in a thickness of one mil, or thicker or thinner, and the layer will adhere firmly to smooth surfaces when dry, and will not loosen when wet, unless pulled or rubbed; when the film is stained with dyestuffs, which necessarily have to be water-insoluble, such dyes will neither stain nor bleed when the film is being wetted for removal. The film can be removed easily at will land in undissolved form and will not get loose unvoluntarily through unfavorable atmospheric conditions.

The organic alkaline material which is added to the copolymer solution may be any nitrogen base; the limitations being only that said nitrogen base is soluble in organic solvents and is substantially non-volatile at 20 to 30 C. at a pressure of 760 mm. mercury; or, for temporary coatings which are needed only over a relatively short period the boiling point being sufficiently high and the vapor pressure being sufficient-ly low, so that a sufficiently large amount of said nitrogen base remains in the film for the needed period to make the coating detachable after wetting with water, without making it necessary to add so much nitrogen base that the coating might become water-soluble. That is normally true for bases with a boiling point of 250 C. or more at 760 mm. mercury pressure. The substantially non-volatile nitrogen bases are solids, or liquids with boiling points of 300 to 360 C. at atmospheric pressure of 760 mm. mercury.

Biases which are even sparingly soluble in organic solvents may be used, as only very small quantities are needed. Such nitrogen bases can be primary, secondary or tertiary amines, and they may be aliphatic, aromatic or heterocycl-ic compounds, including hydroxyl amines and hydrazines, and they may contain 'alky-l, aryl, hydroxyl or other groups or radicals; they may contain more than one amino group or they may be quarternary ammonium bases. All these classes are repeatedly exemplified by the following compounds which have been found to be operable:

Triethylene tetramine; tetnaethvlenepentamine; polyglycolamine H-l63 (HO.CI-I CH OCH CH Ol-i CH CHzNH tetradecylamine; dioctylamine; didecy-lamine; S-isopropylamino-l-pentanol; di(2-ethylhexyl) amine; diethanol amine; diisopropanolamine; triisooctylamine; triethanolamine; di(2-ethylhexyl) ethanolamine; triisopropanolamine; bu-tyldiethanolamine; meta-amino phenyl methyloarbinole; kylidine; u-naphthylamine; S-naphthylamine; p-phenylenediarnine; benzidine; phenylhydrazine; acetoacetanilide; aceto acet ortho anisidide; aceto acet ortho toluidide; aceto racet ortho xylidide; diphenylamine; N,N- dibutyl aniline; amine 220 (017E330 :NC2H4NC 2H4OH) phenyldiethanolamine; phenyl ethyl ethanolamine; trimethylphenyl ammonium hydroxide; diphenyl hydrazine; tetraethyl tetrazine; amylaniline; N-phenyl morpholine; hexamethylenetetnamine; phenazine; aminophenazine; diaminophenazine; naphthazine; ant hrazine iminazol or glyoxalin; 1,2,4 triazole; S-amino tetrazole; quinaldine; ot-hydroxyquinoline; quinine; quinidine; papaven'ne; narcotine; antipyrine, etc. etc.

It is well known that copolymers of vinylacetlate with crotonic acid or maleic acid, copolymerized in the before mentioned ratios dissolve in an excess of aqueous solutions of alkalies, ammonia or certain Water soluble amines, to form water soluble salts.

In the US. Patent No. 2,698,316 it has also been disclosed to react certain amines with the copolymeric reaction products of alpha, beta-unsaturated polycarboxylic acids, in particular, maleic acid, with aliphatic vinyl compounds, in particular, vinyl acetate. According to said disclosure copolymers are being used which are obtained by reacting equimolar quantities of the monomers. The amines with which said copolymers are reacted are saturated primary and secondary aliphatic higher amines containing from 8 to 18 carbon atoms, in particular, an average of 14 carbon atoms. One to two moles of aliphatic primary or secondary amine are reacted with one mole of the unsaturated polybasic acid or anhydride in the copolymer. Expressed in ratios of amine to copolymer, as given by the examples in US. Patent 2,698,316, said ratios are from 200 to 285 parts per weight of amine to 100 parts of copolymer. The reaction between amine and copolymer takes place in a suspension of toluene or xylene at temperatures between 100 C. to 200 C. under reflux and the reaction time is from 1 to 5 hours. The reaction products, after the solvents have been removed, are mostly oils, are all soluble in mineral oils and are being used as pour point depressants and viscosity index improvers for lubricating oils.

The coating compositions of my invention are entirely different from the above mentioned productswhich are presently known to the art. The copolymers which I use for the purpose of my invention contain only from 0.5 to

5.00% of an unsaturated acid containing four carbon atoms, exemplified by crotonic acid, isocro-tonic' acid, fumaric acid and maleic acid; their respective anhydrides for the purpose of this invention being considered equivalent to the acids. I prefer to use a copolymer of 97% vinyl acetate and 3% crotonic acid. I can use such 00- polymers with a molecular weight ranging from 22,000 to 60,000 with a preferred range of 25,000 to 40,000, and particularly of around 28,000.

I can use any nitrogen base with a basic character, from mild to strong bases, which are solid, or liquid and substantially non volatile at temperature of 20 C. to 30 C. at an atmospheric pressure of 760 mm. mercury, and which are sufliciently soluble in organic solvents; sufiioiently soluble in organic solvents for the purpose of this invention means a solubility of not less than 1 part in 100 parts solvent at 20 C. Such nitrogen bases are not limited to primary or secondary amines, neither to aliphatic compounds. Of many hundreds of nitrogen bases which I can use and which are within the given limitations, 52 examples have been listed to represent at least the most important classes of such nitrogen bases.

I dissolve said copolymers and nitrogen bases at room temperature of 20 C. to 30 C. and under normal atmospheric pressure in organic solvents, preferably blended to provide for a quick drying lacquer which deposits a smooth, non-blushing, residual coating. The ratio of such nitrogen base might be from 0.5 part to 10 parts by weight to 100 parts of copolymer; however, the average will be about 1 to 2 parts nitrogen base to 100 parts by weight of copolymer. No heating takes place to react the components. After evaporation of the solvent the residue is a film forming resin which is substantially insoluble in water and mineral oil. However, the properties of the original copolymer have changed in the residual resin.

Though the amount of nitrogen base is insufiioient to possibly form a watersoluble salt with the copolymer in the presenceof water it might be that a fraction of copolymer has arranged itself with the nitrogen base to form a latent compound which is uniformly dispersed in the solvent solution; after evaporation of the solvent such latent particles might be uniformly dispersed in the remaining unreacted part of the copolymer to react in contact with water to form a water-soluble salt which is sparingly, but uniformly interspersed in the water insoluble residue. However, I do not known whether this theory is right or whether a new compound has been formed. There are a number of considerations which are for and against either one of those theories and a confirmation will have to wait until additional investigations will produce new facts.

7 8 However, whatever the correct explanation might be, It would lead unduly far to give examples of every the new product is a truly new and useful product. It possible or even desirable or useful variation of these has been established that films cast from this solution new and improved coating compositions. The following onto smooth, inert surfaces, after being brought into short few examples shall therefore serve only as a sample contact with water, loose temporarily their strong bond demonstration as to how such coating compositions can with the base surfaceand can be easily removed by wipbe made. However, the scope of this invention is by iug, pulling, stripping etc. They become temporarily no means limited to the examples, and it is emphasized soft and extremely stretchable. They do not dissolve in that virtually hundreds of difierent nitrogen bases as Water. When the coating solution is poured into water or previously, described can be combined with any one of carefully cast onto the surface of the water a precipita- 10 the described acid p v i w s t solv nts tion takes place; the same soft, stretchable material forms may greatly vary, depending on the end use of the coatstriugs in the water or a film on the surface of the water, ing solutions, and the addition of additives is optional respectively. A number of practical applications of these i any individual case. Such additives can be any one properties have already been de ribed, of suitable commercial Wetting or dispersing agents, pig- The choice of the solvent vehicle also influences the ments, dye-stuffs Or other rgani 1 inorganic Staining detachability of the film fnom certain base materials. agsms, filtering agents fo any band of the spectrum, per- Thus, if the base material which is to be coated, is inert fumes, Plasticilers to organic solvents, such as glass, metal, stone, poly- Example 1 v of the organic solvent vehicle.

ethylene, the film is easily detachable by applying water, combined with mechanical stripping action, irrespective i P soil/ant veinde 15 as follows; tha P portions of its ingredients being by volume:

However, if the basematerial is sensitive to certain Percent organic solvents, such as base materials which are made Methanol 20 of polystyrene, methyl methacrylate, cellulose acetate, lsopmpanol 50 nitrocellulose, polyvinyl acetate, polyvinyl chloride, and M6thy1 ethyl ketone 15 other plastics or resins, the single or mixed solvent vehicle n'Buty1 acetate 15 0f the Coating lacquer Q composition y Optionally be This solvent is anhydrous or substantially anhydrous. free fnom solvent to which said base material is sensitive. Th ti composition, i parts b weight, consists f The solvents which attack plastics, especially thermoh following; plastic plastics, are usually esters, ketones, aromatic hydrocarbons, and chlorinated hydrocarbons. Most'plas- (A) Sald Solvent tics are inert to alcohols and to straight-chain hydrocar- (B) OI iopolymer bons. Hence if the base material is a plastic, alcohols (C) methanolamme and straightchain hydrocarbons can beused as solvents P 035/0 31,6110, dyesiufi in the coating compositions, or as diluents therein. The (n) 050% blue dyestufl solvent vehicle of the coating composition may consist in The copolymer (B) is made of 97% vinylacetate and whole or in part of alcohols. It is undesirable for some 3% crotonic acid and has an approximate molecular purposes to use a coating composition whose solvent weight of 28,000; this copolymer is hydrophobic and does attacks the base material if a str-ippable film is desired, 40 not hydrolyse in Water; because this prevents easy removal of the film. Also, in The yellow dyestutf (D) is manufactured and sold by such case, if the coating composition includes a dissolved the National Aniline Division of Allied Chemical and dye, such dye will stain the base material. However, the Dye Corporation New York, N.Y., under the name of invention is not limited to any solvent vehicle or to 21 Oi Yellow 3 this is a disaZO y C010111 IHdeX 2nd 'strippa'ble fil edition, number 21,230, also known as Colour Index If the solvent vehicle is a mixture which has a major Solvent Yellow 29; I proportion by volume or weight, or both by volume and Its formula is given in the Colour Index as follows:

OH H30 CH; 110 -C C 1120 CH: i 130-03 oH-oHe zC\ /CH2 H20 OH: V HzC\ 0H,- H2C-CH2 0H2 nic-ofi,

weight, of an alcohol or alcohols, said solvent vehicle 'The blue dyestuif (E) is a 1,4 dialkyl amino anthramay have a minor proportion of ketones, esters, aromatic quinone derivative which is described in U.S.P. 2,211,943; hydrocarbons or chlorinated hydrocarbons. In such case, it is known as Brilliant Oil Blue BMA and manufactured there is no substantial effect on a plastic which is inert to by the Natl. Aniline Div. Allied Chem. & Dye Corp. the alcohol or alcohols, so that the film can be easily 0 Ingredi n s are added in 511606851011 stripped by applying aqueous soap solution with comto Ingredient as at With P p i gbined mechanical action, if an easily strippable film is It isnoted that the weight of the triethanolamine is 1.5% desired. In such case, part of the alcohol or alcohols of the Weight of the Ieeetent resin The concentracan be replaced by straight-chain hydrocarbons to which i of t e reactant amine is 0.15%. a the plastic is inert. The color, gloss and other surface This Coating Composition y be filtsfsd, if necessarycharacteristics of the plastic are thus unaffected by the It Provides a transparent finalrthin film of uniform hi kapplication of the film and its remov l, ness, which has a green color. This coating composi- -If a larger amount of nitrogen base is dissolved than i101] y be pp y brushing, d pp spraying, necessary to make the residual film strippable by apt0 an Object made of 616311 glass and other nonporous plication of Water, without dissolving said film in water, materials, at -3 C- The miXed Solvent is althere is also a latent reaction product formed in the lowed evaporate at 0 C- in air at said normal organic solvent solution. In that case, the latent re atmcspheric pressure- This film has good adherence t action product in said residual film will become water a clear surface of glass, metal, stone, plastics and other soluble and will dissolve after staying immersed in water non-porous materials.

for some time. 1 When this film is wetted with water the film absorbs water, because the film is now hydrophilic. However, the wetted film remains stable and adherent in the absence of mechanical stripping action. Light rubbing, wiping or pulling, easily strips the film. After a short redrying period, the dry film cannot be stripped by mechanical action. The film is substantially insoluble in water at 2 C.30 C.

Example 2 The solvent vehicle or solvent is as follows, the pro- The solvent is anhydrous or substantially anhydrous. The coating composition in parts by weight consists of the following:

Percent (F) Solvent 91.0 (G) Co-polymer 8 (H) Tetraethylenpentamine 0.1 (1) Orange dyestuff 0.9

The co-polymer (G) is made of 98.5% vinyl acetate and 1.5% maleic acid; its molecular weight is approximately 40,000.

The orange dyestufli' is a xanthene dye, Colour Index Number (2nd Ed.) 45,456; it is also known as C & D orange No. 14. Its formula is given in the Amer. Journ. of Pharm. Sept. 1942 as follows:

Br Br HO O OH H000 --C\ COOH This composition is prepared as in Example No. 1. In this case, the weight of the nitrogen base is 1.25% of the weight of the acid resin (G). The concentration of the basic reactant is 0.1% of the Weight of the coating composition.

Properties and applications same as in Example 1.

Example 3 The solvent vehicle or solvent is as follows, the proportions of its ingredients being by volume:

The solvent is anhydrous or substantially anhydrous. The coating composition, in parts by weight, consists of the following:

Percent (J) Solvent 86 (B) Co-polyrner 11 (L) Meta-amino phenyl methyl carbinol 0.6 (M) Blue dyestuff 1.25 (N) Ultraviolet absorber 1.15

The co-polyrner (B) is the same as in Example 1. The blue dyestuif (M) is Victoria Blue 4R base, a triarylpass through both films.

- 10 methane Cl. No. 42,5633 (Solvent Blue 2) with the following formula:

\\ =r ornmoi The ultraviolet absorber (N) is 2,4 dihydroxy benzophenone. The method of preparation is as in Example 1. This composition can be used to form a film on any non-porous surface, including many plastics. In this example, the weight of the nitrogen base is about 5.4% of the acid resin.

Example N0. 4

The solvent vehicle or solvent is as follows, the proportions of its ingredients being by volume:

Percent n-Butyl alcohol 17 Xylene 15 Cellosolve (glycol mono ethyl ether) 38 Methanol 10 Isopropanol l0 Isobutylalcohol 10 The solvent is anhydrous or substantially anhydrous. The coating composition, in parts by weight, consists of the following:

Percent (F) Solvent 78 (B) Co-polymer 11 (C) Triethanolamine 1 (G) Co-polymer 5 (O) Dibutyl phthalate 2.5 (P) Iodine 2.5

Copolymer (B) is the same as in Example 1; Co-polymer (G) is the same as in Example 2. The preparation is the same as in Example 1.

If this solution is cast on a clean glass plate and the solvent is allowed to evaporate, the remaining dry film is transparent and has a light brown color. If said film is wetted with water it can be lifted from the glass plate and at the same time be stretched. When stretched to about 2 /2 times of its original length the stretched, soft film can be transferred to another glass plate. It dries within a short time while kept in the stretched position and now adheres firmly to the transferred glass plate. The film is still transparent and the color has changed to a light, pinkish yellow. This film now polarizes light. If two such films are superimposed with the stretched dimensions parallel to each other incident light can If one film is rotated gradually up to degrees incident light is gradually extinguished; the light extinction reaches a maximum when the films are crossed at 90 degrees. Instead of transferring the stretched film to glass, it can be transferred to a transparent plastic sheet, and the stretched film can also be sandwiched between two transparent sheets. Instead of using two different co-polymers I can use only one in the above formulation.

Example 5 The solvent vehicle or solvent is as follows, the proportions of its ingredients being by volume:

Secondary butyl alcohol 10 1i. The solvent is anhydrous or substantially anhydrous. The coating composition, in parts by weight, consists of the following:

Percent (Q) Solvent"; 87.0 (B) (Io-polymer 10.0 (S) l-amino tetradecane 0.2 (T) Blue dyestuif 0.4 (U) Black pigment 2.4

The co-polymer B) is the same as in Example 1. The blue dyestuff (T) Calcogas Blue NA, an anthroquinone dyestufi made by the Calco Chem. Division of the American Cyanam-id Corp. of New York. C. I. No. 61555, also C. I. Solvent Blue 14, also known as D & C Blue No. 5. The formula is as follows:

V on its thickness. Like the other films, it can be stripped after being wetted with water.

The improved films can be thus used to provide colorless or colored protective films for storing and shipping various'articles and materials.

As one illustration, a glass lens which had a dry coating made according to Example No. 1, was immersed in water at 20 C.30 C., under normal atmospheric pres sure of 760 millimeters of mercury. No perceptible solution of said film in the water was observed at the end of an immersion period of one hour.

The thickness of the film may be from one micron to eighteen microns, with a preferred range of nine microns to fourteen microns. Thicker films may be formed by increasing the solid content and viscosity of the lacquer.

I have described preferred embodiments of my invention, but numerous changes, omissions, additions and substitutions can be made without departing from its scope. V

This application is a continuation-in-part of my application Serial No. 503,034, filed April 21, 1955.

I claim:

1. A liquid coating composition which is a lacquer characterized in that the firm provided thereby upon evaporation of the solvent thereof is insoluble in water and after contact with water is strippable by mechanical action from asurface protected thereby, said composition comprising, as the lacquer solvent, a volatile organic and substantially anhydrous solvent, a resin dissolved in said solvent, and an organic nitrogen base dissolved in said solvent, said resin being a co-polymer of vinylacetate and an unsaturated carboxylic acid containing atotal of four carbon atoms and selected from the group consisting of maleic, fumaric, crotonic and isocrotonic acid, said resin containing from 95% to 99.5% vinylacetate groups and from 0.5% to of said carboxylic acid groups, said organic nitrogen base being substantially non-volatile at C. to 30 C. under normal atmospheric pressure of 760 millimeters of mercury said nitrogen base being 0.5 part to 10 parts by weight to 100 parts by weight of said co-polymer.

2. A coating composition according to claim 1, in which said resin is a co-polymer of vinylacetate and crotonic acid.

3. A coating composition according to claim 1, in which said resin is a co-polymer of vinyl acetate and isocrotonic acid.

4. A coating composition according to claim 1, in which said resin is a co-polymer of vinylacetate and maleic acid.

5. A coating composition according to claim 1, i which said resin is a co-polymer of vinyl acetate and fumaric acid.

6. A coated object, said object having a coating which is a film formed from a composition according to claim 1.

7. A coated object, said object having a coating which is a film formed from a composition according to claim 2.

8. A coat-ed object, said object having a coating which is a film formed from a composition according to claim 3.

9. A coated object, said object having a coating which is a film formed from a composition according to claim 4.

10. A coated object, said object having a coating which is a film formed from a composition according to claim 5.

11. A transparent coated sheet, said sheet having a 'dichroicly stained coating or layer which is a film provided by a lacquer of a composition according to claim 1, said coating being oriented by stretching said coating while in the water-moistened, detached state, said coated sheet having light-polarizing properties.

12. A coating composition according to claim 1, in

which the weight of said resin is 10 to 100' times the Weight of said nitrogen base.

13. A liquid coating composition which is a lacquer characterized in that the film provided thereby upon evaporation of the solvent thereof is insoluble in water and after contact with water is strippable by mechanical action from a surface protected thereby, said composition comprising, as the lacquer solvent, a volatile organic solvent containing less than 5% water, a resin dissolved in said solvent and an organic nitrogen base dissolved in said solvent, said resin being a co-polymer of vinylacetate and an unsaturated carboxylic acid containing a total of four carbon atoms and selected from the group consisting of rn'aleic, fumaric, crotonic, and isocrotonic acid, and being non-hydrolyzable in water, said resin con- I taining from to 99.5% vinylacetate groups and from 0.5 to 5% of the carboxylic acid groups, said nitrogen base being 0.5 part to 10 parts by weight to parts by weight of said co-polymer, said organic nitrogen base being substantially non-volatile at 20 C. to 30 C. under normal atmospheric pressure of 760 millimeters of mercury, and being soluble in said solvent in amount of at least 1 part of nitrogen base in 100 parts of solvent.

14. A coating composition according to claim 13, in which said resin is a co-polymer of vinyl acetate and crotonic acid.

15. A coating'composition according to claim 13, in which said resin is a co-polymer of vinyl acetate and isocrotonic acid.

16. A coating composition according to claim 13, in which said [resin is a co-polymer of vinyl acetate and maleic acid.

11 A coating composition according to claim 13, in which said resin is a co-polyrner of vinyl acetate and furnaric acid.

18. A coated object, said object having a coating which is a film formed from a composition according to claim 13.

19. A coated object, said object having a coating which is a film formed from a composition according to'claim 14.

20. A coated object, said object having a coating which is a film formed from a composition according to claim 15 21. A coated object, said object having a coating which is a film formed from a composition according to claim 16.

22. A coated object, said object having a coating which is a film formed from a composition according to claim 17.

13 14 23. A transparent coated sheet, said sheet having a di- References Cited in the file of this patent chroicly stained coating or layer which is a film provided UNITED STATES PATENTS by a lacquer composition according to claim 13, said coating being oriented by stretching said coating while 2,562,852 Baer July 31, 1951 in the water-moistened, detached state, said coated sheet 5 2,698,316 Giammaria Dec. 28, 1954 having light-polarizing properties. 2,806,020 Scott et a1. Sept. 10, 1957 

13. A LIQUID COSTING COMPOSITION WHICH IS A LACQUER CHARACTERIZED IN THAT THE FILM PROVIDED THEREBY UPON EVAPORATION OF THE SOLVENT THEREOF IS INSOLUBLE IN WATER AND AFTER CONTACT WITH WATER IS STRIPPABLE BY MECHANICAL ACTION FROM A SURFACE PROTECTED THEREBY, SAID COMPOSITION COMPRISING, AS THE LACQUER SOLVENT, A VOLATILE ORGANIC SOLVENT CONTAINING LESS THAN 5% WATER, A RESIN DISSOLVED IN SAID SOLVENT AND AN ORGANIC NITROGEN BASE DISSOLVED IN SAID SOLVENT, SAID RESIN BEING A O-POLYMER OF VINYLACETATE AND AN UNSATURATED CARBOXYLIC ACID CONTAINING A TOTAL OF FOUR CARBON ATOMS AND SELECTED FORM THE GROUP CONSISTING OF MALEIC, FUMARIC, CROTONIC, AND ISOCROTOLLIC ACID, AND BEING NON-HYDROLYZABLE IN WATER, SAID RESIN CONTAINING FROM 95% TO 99.5% VINYLACETATE GROUPS AND FFROM 0.5 TO 5% OF THE CARBOXYLIC ACID GROUPS, SAID NITROGEN BASE BEING 0.5 PART TO 10 PARTS BY WEIGHT OF 100 PARTS BY WEIGHT OF SAID CO-POLYMER, SAID ORGANIC NITROGEN BASE BEING SUBSTANTIALLY NON-VOLATILE, AT 20*C. TO 30*C. UNDER NORMAL ATMOSPHERIC PRESSURE OF 760 MILLIMETERS OF MERCURY, AND BEING SOLUBLE IN SAID SOLVENT IN AMOUNT OF AT LEAST 1 PARTS OF NITROGEN BASE IN 100 PARTS OF SOLVENT. 